A (probably) incomplete list of (start-up) companies related to NoCs:
Intel (“Knights Landing” Xeon Phi)
GreenArrays – Can anyone figure out how their 144 cores on G144 chip communicate with each other?
Also, here is a list of NoC related EDA tools. This list could be very well included as a subsection of Simulators post. However, it is included here because these are tools from companies.